Frank, they are like any other engine and respond in the same way to the same kind of mods. Where they differ is the scope of those mods. Slants are easily "overbuilt". In other words, easily overcammed, overcarbureted, over exhausted. You get the idea. The best thing to do is figure out what you want to do with the car and go from there. Get what's there now running in top tune so you have a solid baseline. If you can be more specific about your goals, you can get some much more specific answers. We have some real slant gurus here that are always willin to lend a hand. I am building one myself...my first slant in fact. It's gonna be a hot one, but I don't have experience with them. I am relying on friends to help me along. They have been a tremendous help so far.